• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.331-336
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• 1991

In order to utilize natural cellulosic materials as a fermentative substrate, saccharification of a various kind of native cellulosic materials was performed by using cellulase from the isolated strain, Pseudomonas sp. LBC-505 which potently produced cellulase complex and xylanase. Cellulase complex production was repressed by the low concentration of glucose, induced by cellulosic compounds such as CMC, wheat bran and rice straw et al. and showed to be highest on the PY-CMC medium containing 5% (w/v) wheat bran instead of CMC. Optimal temperature for enzyme reactions of CMCase and xylanase was $50^{\circ}C$, and $55^{\circ}C$ for $\beta$-glucosidase. Optimal pH for these enzyme reaction was 6.6. Rate of saccharification for natural cellulose was low by the treatment of crude enzyme. Among their substrates, rice straw was the most effective substrate of enzymatic reaction in this work. After treating rice straw with 5% (v/v) HC1 and hydrolysing with crude enzyme, rate of saccharification was 18.4% (w/w) on dry substrate. Sugars of cellulosic hydrolyzate mainly contained glucose, xylose and cellobiose.

• Microbiology and Biotechnology Letters
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• v.14 no.5
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• pp.399-405
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• 1986

Corn starch was saccharified without cooking in an agitated bead reaction system. Uncooked corn starch was effectively hydrolyzed even at the concentration as high as 39%(w/v). After 24 hours. the extent of saccharification reached at 92%, which corresponds glucose concentration of 425g/L. Fed-batch feeding of starch was more effective than batch feeding for saccharification of uncooked corn starch. The composition of hydrolysated of uncooked starch was analyzed. which was composed of 95% glucose, 0.7% of maltose, and 4.5% of high saccharide, similar with that of cooked starch. The hydrolysate can be successfully utilized for HFCS manufacture. The starch liquefying and saccharifying enzyme was relatively stable even be the physical impact of the attrition-milling media. The enzyme stabilizer, $Ca^{++}$, played an essential role in preventing the enzyme deactivation caused by the physical impact.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1427-1437
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• 2014

Enzymatic hydrolysis of lignocellulosic biomass into fermentable sugars is a key step in the conversion of agricultural by-products to biofuels and value-added chemicals. Utilization of a robust microorganism for on-site production of biomass-degrading enzymes has gained increasing interest as an economical approach for supplying enzymes to biorefinery processes. In this study, production of multi-polysaccharide-degrading enzymes from Aspergillus aculeatus BCC199 by solid-state fermentation was improved through the statistical design approach. Among the operational parameters, yeast extract and soybean meal as well as the nonionic surfactant Tween 20 and initial pH were found as key parameters for maximizing production of cellulolytic and hemicellulolytic enzymes. Under the optimized condition, the production of FPase, endoglucanase, ${\beta}$-glucosidase, xylanase, and ${\beta}$-xylosidase was achieved at 23, 663, 88, 1,633, and 90 units/g of dry substrate, respectively. The multi-enzyme extract was highly efficient in the saccharification of alkaline-pretreated rice straw, corn cob, and corn stover. In comparison with commercial cellulase preparations, the BCC199 enzyme mixture was able to produce remarkable yields of glucose and xylose, as it contained higher relative activities of ${\beta}$-glucosidase and core hemicellulases (xylanase and ${\beta}$-xylosidase). These results suggested that the crude enzyme extract from A. aculeatus BCC199 possesses balanced cellulolytic and xylanolytic activities required for the efficient saccharification of lignocellulosic biomass feedstocks, and supplementation of external ${\beta}$-glucosidase or xylanase was dispensable. The work thus demonstrates the high potential of A. aculeatus BCC199 as a promising producer of lignocellulose-degrading enzymes for the biomass conversion industry.

• KSBB Journal
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• v.4 no.3
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• pp.276-280
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• 1989

The effect of the pretreatment by solvent extraction on the saccharification of poplar (Populus euramencana) was studied. The solvent system was Phenol/H2O(Uncatalyzed)and Phenol/H2O/HCl catalyst system. When the poplar was pretreated by uncatalyzed system, the best result of the saccharification was total of 43.9 g/1 reducing sugar produced and 83.5% of carbohydrated conversion was obtained at 19$0^{\circ}C$, 60 minutes. Total wood yield and the lignin removal were 46.3% and 98.2% respectively. The use of acid catalyst was unsuitable to increase he efficiency of saccharification.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.437-444
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• 1992

An innovative process for high fructose corn syrup (HFCS) production coupled with direct saccharification of raw corn starch in the agitated bead enzyme reactor (bioattitor) was investigated. The required high concentration/purity of glucose solution suitable for isomerization was produced directly in a bioattritor. without condensation of hydrolyzate, 398 g glucose/$\ell$ and 98% glucose content from 400 g/$\ell$ (w/v) of raw corn starch after 24 hours. The unsaccharified residual starch could be separated easily upon centrifugation, and resaccharified. The obtained solution also possessed other desirable requirements as substrate for isomerization, such as. low concentrations of denatured protein and calcium ions, thereby, simplified the purification step. The obtained glucose solution was isomerized in an enzyme reactor paked with immobilized glucose isomerase to evaluate the suitability as a substrate. The proposed new HFCS process seems to have many advantages over the conventional process via liquefaction-saccharification steps. The follow-up investigations of the proposed process need to be conducted to evaluate the feasibility of industrial application.

• Journal of the Korean Wood Science and Technology
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• v.37 no.4
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• pp.381-387
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• 2009

Enhancing enzymatic saccharification of corn stover by aqueous ammonia soaking pretreatment was investigated on chemical compositional changes and enzymatic hydrolysis characteristics. At three different levels of aqueous ammonia soaking temperature and time ($140^{\circ}C$-1 h, $90^{\circ}C$-16 h and $50^{\circ}C$-6 days), higher temperature and shorter treatment time led to more xylan and lignin removal based on overall composition analysis and carbohydrate compositional analysis. More xylan and lignin removal in higher temperature treatment led to higher enzymatic saccharification of cellulose and xylan to monosaccharide by commercial cellulase mixtures (Celluclast 1.5L and Novozym 342 from Novozyme, Denmark).

• Journal of Microbiology and Biotechnology
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• v.23 no.3
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• pp.351-356
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• 2013

A high ${\beta}$-glucosidase (BGL)-producing strain, Stereum hirsutum, was identified and isolated and showed a maximum BGL activity (10.4 U/ml) when cultured with Avicel and tryptone as the carbon and nitrogen sources, respectively. In comparison with other BGLs, BGL obtained from S. hirsutum showed a higher level of activity to cellobiose ($V_{max}$ = 172 U/mg, and $k_{cat}$ = 281/s). Under the optimum conditions (600 rpm, $30^{\circ}C$, and pH 6.0), the maximum BGL activity of 10.4 U/ml with the overall productivity of 74.5 U/l/h was observed. BGL production was scaled up from a laboratory scale (7-L fermenter) to a pilot scale (70-L fermenter). When S. hirsutum was cultured in fed-batch culture with rice straw as the carbon source in a 70-L fermenter, a comparable productivity of 78.6 U/l/h was obtained. Furthermore, S. hirsutum showed high levels of activity of other lignocellulases (cellobiohydrolase, endoglucanase, xylanase, and laccase) that are involved in the saccharification of biomasses. Application of S. hirsutum lignocellulases in the hydrolysis of Pinus densiflora and Catalpa ovata showed saccharification yields of 49.7% and 43.0%, respectively, which were higher than the yield obtained using commercial enzymes.

• Korean Journal of Microbiology
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• v.52 no.2
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• pp.220-225
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• 2016

To improve antioxidant glutathione (GSH) content and saccharification ability in sake yeasts of Saccharomyces cerevisiae, the ${\gamma}$-glutamylcysteine synthetase gene (GSH1) from S. cerevisiae, glucoamylase gene (GAM1) and ${\alpha}$-amylase gene (AMY) from Debaryomyces occidentalis were co-expressed in sake yeasts for manufacturing a refreshing alcoholic beverage abundant in GSH from rice starch. The extracellular GSH content of the recombinant sake yeasts increased 1.5-fold relative to the parental wide-type strain. The saccharification ability by glucoamylase of the new yeast strain expressing both GAM1 and AMY genes was 2-fold higher than that of the yeast strain expressing only GAM1 gene when grown in the culture medium containing 2% (w/v) rice starch. It generated 11% (v/v) ethanol from 20% (w/v) rice starch and consumed up to 90% of the starch content after 7 days of fermentation.

• Journal of Mushroom
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• v.18 no.4
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• pp.357-364
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• 2020

The grade and price of Lentinula edodes largely differs in preference depending on the product area and seasonal factors. The product amount of autumn L. edodes was higher than that of spring L. edodes, but high quality, which is divided into "Hwago" is low in preference. Mostly, the autumn L. edodes is obtained as powder; hence, it is necessary to develop a processing method to utilize its flavor and aroma at an affordable price. Additionally, we estimated the content of 𝛽-glucan, ergosterol, vitamin D₂, reducing sugars, and free amino acids and evaluated the anti-inflammatory activity of saccharification powder of log-cultivated L. edodes. In the saccharification powders obtained via 7 min of UV irradiation of log-cultivated L. edodes, 𝛽-glucan and vitamin D₂ contents were found to be the highest, whereas ergosterol content was found to be the lowest. The content of reducing sugars ranged from 62.4 mg/L to 68.2 mg/L. The free amino acids were higher in these saccharification powders than in the control. Subsequently, RAW 264.7 cells were treated with different concentrations (10, 50, 100, 200, 300, and 500 ㎍/mL) of the saccharification powders of log-cultivated L. edodes obtained via different UV irradiation time applications. The cells showed good viability; the anti-inflammatory effect was found to be the highest at 7 min UV irradiation. Therefore, 7 min of UV irradiation was determined to be the optimum condition for manufacturing saccharification powders of log-cultivated L. edodes. Hence, saccharification powders of log-cultivated L. edodes may be used as a raw material for natural sweeteners, food additives, and in the food industry.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.4
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• pp.21-29
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• 2015

In this study, the feasibility of utilizing wood chips from pitch pine (Pinus rigida) was evaluated for bioethanol production by an organosolv pretreatment and enzymatic saccharification. When wood chips from pitch wood were pretreated with 75% (v/v) ethanol and 1.7% sulfuric acid as a catalyst at H-factor 2000, average pulp yield was 43.3%, which pretreated wood fibers showed higher glucan (55.8%) and lower lignin (12.2%) contents than untreated control (43.9% glucan and 27.8% lignin). After enzymatic saccharification, the organosolv pulps with 56.2% delignification rate reached above 97% conversion rate of cellulose to glucose. These results indicated that increasing the delignification rate causes micro pores on the surface of organosolv pulps resulting in improved the accessibility of enzyme onto the substrate. Moreover, it was in agreement with the SEM examination of wood fibers.